All About Relationship Testing

Your DNA can be used to test other family relationships, in addition to paternity testing. There are currently several relationship tests currently on the market, and we provide details for six of them here.

Maternity Testing

A maternity test is similar to a paternity test. The difference is that an alleged mother is being tested, not an alleged father. The collection process and the testing process are very much the same. In a maternity test, the child and alleged mother are tested. The participation of the father is often encouraged, but it is not required for a conclusive answer.

Maternity testing is useful in cases where an individual has been separated from their mother from an early age, often because of adoption or other extenuating circumstances. For example, in many U.S. states, adoption records have been sealed, and only a maternity test can provide a definitive answer.

Grandparentage Testing

Sometimes grandparents want to make sure their grandchild is actually their biological grandchild, or perhaps the alleged father is missing or deceased but his parents are available for testing, the paternal grandparents can be tested together with the child to determine if they have a biological relationship. This test is very important for many people because they might not realize they still have a viable testing option, even in unusual circumstances.

Maternal grandparentage tests may also be used to determine family relationships in situations where an alleged mother is not available for testing. If the child's mother is unavailable or would prefer not to participate in the test, we can perform a motherless grandparentage test.

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Siblingship Testing

A siblingship test determines if two or more individuals are half siblings or full siblings. This test is often used to confirm biological relationships among adoptees and siblings. It can also be used to infer paternity in cases where the alleged father is unavailable for testing.

The participation of any available, known parents is strongly encouraged because the DNA loci that siblings inherit from their father and mother may be completely different. The probability of obtaining conclusive results is always improved when the known parents participate in the test.

Siblingship testing is highly complex, and it requires sophisticated analysis and interpretation of the DNA testing data. Such testing services require an experienced, qualified DNA test laboratory staff.

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Twin Zygosity Testing

Twin zygosity tests are for parents of twins or twins interested in knowing if they are identical (monozygotic) or fraternal (dizygotic). The results of the test are usually used to satisfy personal curiosity, but there can be health advantages as well. Identical twins, because their genetic makeup is exactly the same, can always act as organ, tissue, or blood donors for each other. Identical twins are also likely to develop the same genetic disorders; if a disorder is exhibited in one twin, the it is likely that the other twin will develop it as well.

A twin zygosity test will help parents or twins themselves better prepare for the future, providing additional genetic information and medical history.

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mtDNA Testing

Men and women both have mitochondrial DNA (mtDNA) that they received from their mothers, but men cannot pass it on to their children. Mothers pass copies of their own mtDNA to each of their sons and daughters, but only their daughters can in turn pass it on to their children. Thus, mtDNA can be used to track maternal lineage (to see if two or more females are related through their mothers).

This test is often used to establish maternity when the alleged mother is not available for testing or to validate biological relationships when the alleged mother is unable to take part in the DNA test. For example, if an adoptee finds her biological family, but her mother is deceased, she can have mtDNA testing to ensure there is indeed a biological relationship.

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Y-STR Testing

The Y chromosome is passed down through the generations from father to son, and it does not change very much between generations. Thus, the Y chromosome can be used to track paternal lineage (to see if two or more males are related through their fathers).

This test is often used to infer paternity when the alleged father is not available for testing or to validate biological relationships when the alleged father is unable to take part in the DNA test. For example, if the alleged father is deceased, a Y-STR test can be done with one of the alleged father's other male relatives to see if there is a biological relationship with the child.

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